Unmanned Underwater Vehicle (UUV) technology is currently under development for use in industry and the military. Autonomous devices are equipped to navigate under water without an operator on board, and without direct continuous input from a remote operator. Examples are illustrated in U.S. Pat. Nos. 5,690,014 and 5,675,116 (U.S. Navy), and in U.S. Pat. Nos. 8,205,570 and D578,463 (Vehicle Control Technologies Inc.). Devices currently in production for civilian industrial use are the REMUS 600™, manufactured by Kongsberg Maritime in Kongsberg, Norway; the HarborScan™ UUV, manufactured by Vehicle Control Technologies Inc., Reston Va., U.S.A.; and the BlueFin™ model 12D, manufactured by Bluefin Robotics Corp., Quincy Mass., U.S.A.
Another platform currently under development is the LDUUV (Large Displacement UUV) by the Office of Naval Research, Arlington Va., U.S.A. In a current embodiment, the LDUUV is approximately 20 feet long and weighs several tons, which limits its range and the durability of missions before maintenance or refueling. The Office of Naval Research has published the Navy research initiative ONR BAA 11-025 describing future objectives of the UUV program.
A previously unrelated field of nautical technology is vessels that derive locomotive thrust from wave motion. As a wave travels along the surface of water, it produces vertical motion. The amplitude of the vertical motion decreases with depth; at a depth of about half the wave length, there is little vertical motion. The speed of currents induced by wind also decreases sharply with depth.
Various devices have been designed and proposed to harness wave power to do useful work. For example, U.S. Pat. Nos. 986,627, 1,315,267, 2,520,804, 3,312,186, 3,453,981, 3,508,516, 3,845,733, 3,872,819, 3,928,967, 4,332,571, 4,371,347, 4,389,843, 4,598,547, 4,684,350, 4,842,560, 4,968,273, 5,084,630, 5,577,942, 6,099,368 and 6,561,856; U.S. published applications US 2003/0220027 A1 and US 2004/0102107 A1; and international published applications WO 1987/04401 and WO 1994/10029.
Wave-powered vessels have been described in U.S. Pat. No. 7,371,136; U.S. Pat. No. 8,043,133; and published applications US 2008/188150 A1; US 2008/299843 A1; and WO 2008/109022. Exemplary vessels are manufactured and sold by Liquid Robotics, Inc., Sunnyvale Calif., USA under the brand Wave Glider®.